a story from our chief science correspondent, robert bazell. >> reporter: today's study addresses two of the biggest concerns about the flu vaccine and pregnancy. the conclusion, the vaccine is safe, both for pregnant women and their unborn children. >> by getting an influenza vaccine, mothers are not only protecting themselves, but they're protecting the baby too. >> reporter: valerie isabelle was born quite healthy on tuesday. her mother, layla, got a flu shot back in october. >> i got it before the flu season started, when i was a little shy of seven months. >> reporter: this study, the largest to date, looked at more than 117,000 pregnancies in norway, which has free health care and keeps excellent medical records. the study found that women who contracted the flu while pregnant had almost twice the chance of a miscarriage. but even as they got the flu, after getting vaccinated, the chance of miscarriage still went down. and most important, it showed the flu shot itself did not increase the chance of miscarriage or put the baby at risk. for the babies whose moms got the vaccine, t